1. Field of the Invention
This invention relates to a lens grinding apparatus for grinding an unprocessed eyeglass lens with a grinding wheel based on lens shape data, particularly to a grinding fluid supply apparatus of the lens grinding apparatus for supplying grind fluid to the eyeglass lens or the grinding wheel.
2. Description of the Prior Art
As shown in Japanese Patent Laid-Open No. 9(1997)-225828, a lens grinding apparatus has been heretofore known, which grinds an unprocessed eyeglass lens as a material to be ground while supplying grinding fluid to a convex surface (font surface) or a concave surface (rear surface) of the eyeglass lens.
As shown in Japanese Patent Laid-Open Nos. 60(1985)-227223, 61(1986)-8273, 3(1991)-202274, and 5(1993)-31669, a grinding apparatus for an optical lens or the like has been known, in which grinding fluid is supplied to a contact position of a grinding wheel and an optical lens as a material to be ground from a tangent direction of the grinding surface of the grinding wheel.
However, in the above-described lens grinding apparatus, in some cases, the grinding fluid does not sufficiently spread over each of the eyeglass lens and the grinding surface of the grinding wheel because the grinding fluid is supplied to each of the convex (front) and the concave (rear) surfaces of the eyeglass lens.
In the grinding apparatus for an optical lens or the like, when the grinding apparatus is designed so that the grinding fluid directly lashes the grinding wheel, a cooling effect of eliminating frictional heat accompanied with the grinding can be sufficiently obtained, but the grinding fluid splashes with rotation of the grinding wheel and the optical lens as a material to be ground.
Particularly, in the grinding of the eyeglass lens or the like, the grinding fluid sometimes does not sufficiently spread over each of the eyeglass lens or the like and the grinding wheel because of a slight dislocation in a tangent direction between the grinding wheel and the eyeglass lens or the like as a material to be ground, and a shortage of the grinding fluid may occur. In other words, it is difficult to cope with a shift of a processing point of the grinding wheel caused by a difference in the finished shape (lens shape) of the eyeglass lens or the like, namely, a supply of the grinding fluid to such shifted processing point is difficult,
A first object of the present invention is to solve the above-described problem and provide a grinding fluid supply device of a lens grinding apparatus, in which, even when the grinding fluid is allowed to directly lash the grinding wheel, splashing of the grinding fluid can be prevented, and the sufficient grinding fluid can be supplied to both of the eyeglass lens which is a material to be ground and the grinding surface of the grinding wheel.
A second object of the present invention is to solve the problem that, particularly in the grinding of the eyeglass lens as a material to be ground or the like, the grind fluid sometimes does not sufficiently spread over each of the eyeglass lens or the like and the grinding wheel because of a slight dislocation in a tangent direction between the grinding wheel and the eyeglass lens or the like, thus leading to a shortage of the grinding fluid and to provide a grinding fluid supply device of a lens grinding apparatus, in which, even when the processing point of the grinding wheel is moved because of the difference in the finished shape (lens shape) of the eyeglass lens or the like, the grinding fluid can be supplied while following the moved processing point.
In order to achieve the objects, the grind fluid supply device of a lens grinding apparatus according to the present invention comprise first grinding fluid supply means for supplying a grinding fluid in a tangent direction of a circular grinding wheel, which has a grinding surface formed on its circumferential surface, with an interval above a grinding surface and allows an upper portion and a rear side portion of the grinding surface to be covered with a curtain of the grinding fluid spaced from the grinding wheel when a processed lens is subjected to a grind processing with the grinding surface of the grinding wheel by rotatively driving the grinding wheel around an axis; and second grinding fluid supply means for insufflating the grinding fluid to the grinding surface.
Herein, the first and the second grinding fluid supply means are integrally provided.
Moreover, the first grinding fluid supply means discharges the grinding fluid in an arc shape along the grinding surface.
Moreover, the second grinding fluid supply means insufflates the grinding fluid to the grinding surface from a normal direction.
Moreover, a width of the grinding fluid discharged from the first grinding fluid supply means is larger than that of the grinding fluid discharged from the second grinding fluid supply means.
Moreover, a width of the grinding fluid discharged from the second grinding fluid supply means is made approximately equal to that of the grinding surface or larger than that of the grinding surface.
Furthermore, third grinding fluid supply means is provided at a lower edge portion of a rear wall of a processing chamber where the grinding wheel is disposed. The third grinding fluid supply means discharges a grinding fluid to a bottom wall in a width direction of the bottom wall of the processing chamber and flows the discharged grinding fluid to the grinding wheel side along the bottom wall.
Still furthermore, the third grinding fluid supply means is a grinding fluid discharge nozzle provided at a center of the rear wall in a transverse direction.